A three-node vSAN OSA cluster with business critical intensive I/O workload is running out of...

The correct answer is D, add additional capacity disks to each disk group. This is because adding capacity disks to existing disk groups is the fastest and easiest way to expand the capacity of the vSAN datastore without disrupting any ongoing operations or requiring additional hardware. The administrator can add up to five capacity disks per disk group in vSAN OSA, which means each host can have up to 25 capacity disks in total. The administrator should make sure that the new capacity disks are unformatted and not partitioned, so that vSAN can recognize and claim them. The administrator should also manually rebalance the cluster after adding the capacity disks to distribute the data evenly across the new devices. The other options are incorrect for the following reasons:

A, enable Deduplication and Compression on the cluster level, is incorrect because enabling Deduplication and Compression is not a recommended way to expand the capacity of the vSAN datastore. Deduplication and Compression is a space efficiency feature that reduces the logical space consumption of data by eliminating duplicate blocks and applying compression algorithms. However, enabling Deduplication and Compression requires a full data evacuation and resynchronization, which can be disruptive and time-consuming. Deduplication and Compression also introduces additional CPU and memory overhead, which can affect the performance of the cluster. Deduplication and Compression is only supported on all-flash clusters, not on hybrid clusters.

B, add additional capacity by adding a disk on one host and creating a storage pool, is incorrect because creating a storage pool is not supported in vSAN OSA. A storage pool is a new configuration introduced in vSAN 8 ESA, where all disks are treated as capacity disks and use a new algorithm to distribute data acrossthem. This configuration is not compatible with vSAN OSA, which uses a disk group configuration where one disk is designated as a cache disk and the rest are capacity disks. To use a storage pool, the administrator would need to migrate to vSAN 8 ESA on a new cluster with new hardware.

C, add additional capacity by adding a vSAN ReadyNode to the cluster, is incorrect because adding a vSAN ReadyNode to the cluster is not the fastest or easiest way to expand the capacity of the vSAN datastore. A vSAN ReadyNode is a preconfigured server that meets the hardware requirements for running vSAN. Adding a vSAN ReadyNode to the cluster would require additional hardware procurement, installation, and configuration. It would also increase the compute capacity of the cluster, which may not be necessary for the workload. Adding a vSAN ReadyNode would also trigger a resynchronization of data across the cluster, which can affect the performance and availability of the cluster. References:

VMware vSAN Specialist v2 Exam Preparation Guide, page 10